1. Field of the Invention
This invention relates to food products and to their methods of preparation. More particularly, the invention is directed to fruit products, particularly dehydrated, to cereal products containing such fruit products, particularly R-T-E dry breakfast cereals, and to the methods of preparing such products.
2. The Prior Art
Fruit and fruit products enjoy widespread consumer appeal due in part to the wholesomeness and organoleptic attributes of fruit. However, due to the limited shelf life of fruits, efforts from time immemorial have been made to extend the storage of fruits, including, for example, canning, freezing and drying.
Drying long has been the most common technique to prepare fruit products which do not require special packages or storage conditions. Dehydrated fruit products such as apples, raisins, prunes, and the like are popular snack items. Also, the combination of fruit and dry, ready-to-eat ("R-T-E") cereal has significant consumer appeal. Although enjoying some consumer acceptance, food products, particularly R-T-E cereals, containing dried fruit products face problems inherent in combining diverse, dried food materials.
For example, for a stable, crisp, R-T-E cereal, the moisture content is reduced so that the water activity ("A.sub.w ") ranges between 0.2 to 0.4 typically to levels of 1-4%. Fruit conventionally dehydrated to comparable water activity levels are usually hard and/or very tough in texture and fibrous in structure and thus unsuitable for combining with the cereals. Moreover, the flavor progressively deteriorates with greater drying. If, however, fruit pieces are only dried to higher A.sub.w 's so as to retain desirable texture and flavor eating qualities, then they will either not be bacteriologically stable at room temperatures, or when admixed with the dry cereal, will tend over time to lose moisture to the relatively drier cereal and thus cause the cereal to become less crisp or soggy and the fruit to become again hard, dry and excessively tough.
A wide variety of methods are used or have been suggested for use to provide shelf stable fruit or fruit products suitable for incorporation into R-T-E cereal products. Generally, one or more of three basic approaches have been taken. One basic approach has been made to attempt to modify the texture of low water activity fruits. For example, in U.S. Pat. No. 3,453,118 (issued July 1, 1969 to Jobin) low moisture raisins are treated with either acidic or basic baths for brief periods to maintain softness. Post dehydration treatment tends, however, to result in loss of product identity.
A second basic approach has been to dry fruits only partially to maintain good flavor and texture while treating the fruit pieces to enhance either bacterial stability and/or to bind the higher moisture content so as to lower water activity by infusion of sugars and/or humectants, e.g., polyol. For example, U.S. Pat. No. 4,256,772 (issued Mar. 17, 1981 to Shanbhag and Szczesniak) wherein fruits are infused with polyols and sucrose. U.S. Pat. No. 3,952,112 (issued Apr. 20, 1976 to Fulger) discloses processing to increase humectant absorbtion. For certain fruits, i.e., grapes, having an intact skin, an acid treatment step prior to infusion to open the skin to infusion has been taught (see U.S. Pat. No. 4,103,035, issued July 25, 1978 to Fulger et al.).
A third basic approach is to radically restructure the dried fruit piece to improve texture. U.S. Pat. No. 4,055,675 (issued Oct. 25, 1977 to Popper et al.) discloses processes for preparing puffed raisins. U.S. Pat. No. 3,833,747 (issued Sept. 3, 1974 to Cording and Eskew) also discloses processes for preparing puffed dried fruit. U.S. Pat. No. 3,315,619 (issued Apr. 25, 1967 to Slaybaugh) discloses a simulated fruit product comprising fruit puree and structured with starch and gums.
All of these approaches of the prior art attempt to overcome one or more of the deficiencies in stability, texture, flavor and/or color in dried fruits and claim improvements in one or more of these properties. The sheer variety and number of approaches taken each suggest the difficulty in preparing shelf stable dried fruit product having an overall improvement in these properties. Notwithstanding the claimed benefits of the prior art attempts, there is a continuing need for new and useful processes for the preparation of high quality dried fruit.
The present invention thus surprisingly provides improved dried fruit products, an improved process for preparing shelf stable fruit, and R-T-E cereals containing such fruit. The present process provides fruit pieces of soft texture at low A.sub.w with improved natural flavor but without having objectionable off-flavors due to addition of humectants. The present fruit piece products surprisingly are readily recognizable from both visible and flavor standpoints as shelf stable pieces of the fruits from which they are derived and thus do not exhibit loss of product identity. Moreover, the texture improvement advantages are realized without requiring radical restructuring of the dried fruit piece. Indeed the most dramatic improvements in product attributes provided by the present fruit products compared to prior art is in texture or "bite." In certain preferred embodiments, shelf stable fruit pieces are provided without any additives and thus are stylized as being "all-natural."